I've got this 1kw MH ballast that I've been running for a few years now with a single, 400w MH bulb. I use the 400w because 1000w of MH turns my 28x28" growing area into an easy-cook oven, and because I believe that I end up with close to the same effective lumens as the 1000w by bringing the bulb closer to the plants. The 400w is the standard "blue spectrum" kind that's discussed here a lot. I think I'd like to add some red spectrum for flowering. I've been reading this forum about mercury vapor, HPS, and other technologies. What I'd like to do is use the same ballast for the red light, since the "day" period would be the same for the red/blue combination, and because I already have the ballast, and it's less than half-used at the present 400w.

What I need to know is: Can these other kinds of lights (HPS, MV, etc) be run off the same MH ballast, or is that just a silly thought?

What about these "red" MH bulbs such as are up on ebay (SUNMASTER RED BURNING 400w METAL HALIDE Grow Light Bulb CONVERSION LAMP THAT RUN ON A METAL HALIDE BALLAST Item number: 7746017555) (http://cgi.ebay.com/ws/eBayISAPI.dll...IN_Stores_IT)?

Do I still want to use the blue spectrum of the existing bulb and "add" red, or do I want to replace the blue bulb with the red one?

wooohooo! I love experimenting! Mebbe I needs a life. . .

. .. anyway, all input appreciated!
rodekyll Reviewed by rodekyll on . LIGHTING QUESTIONS I've got this 1kw MH ballast that I've been running for a few years now with a single, 400w MH bulb. I use the 400w because 1000w of MH turns my 28x28" growing area into an easy-cook oven, and because I believe that I end up with close to the same effective lumens as the 1000w by bringing the bulb closer to the plants. The 400w is the standard "blue spectrum" kind that's discussed here a lot. I think I'd like to add some red spectrum for flowering. I've been reading this forum about mercury Rating: 5